A major cause of vessel sinking is the failure to close seacocks when the vessel is at anchor or docked. Recent insurance industry estimates report that for every boat that sinks at sea four boats sink while safely moored at their slips. Of those that are safely moored at their slips half of these sinkings are due to seacock failure. Thus for every boat that sinks at sea there are at least two that sink because their seacocks fail while they were sitting at the dock.
The failure of seacocks happens for two main reasons; a leak in the seacock or a leak in the line or hose from the seacock to the device or unit that the seacock is coupled to. Thus, for instance, a hose that is coupled to a seacock and is run to a device or a unit may come off of the seacock due to improper double-clamping. Secondly, even if the hose to the seacock is intact, if the hose lets loose from the device or unit to which it is attached and then extends down below the water line the vessel will fill with water and sink.
A major problem with manually operated seacocks is that they are very inaccessible and must often times be closed with a wrench that may be temporarily lost. Thus, in an emergency there may be no manual way to close up all the seacocks to prevent flooding, Moreover, one may not want to close all of the seacocks involved if it can be ascertained which seacock is responsible for the vessel flooding.
An electric solenoid system exists to close seacocks. However electricity may not be available as a vessel floods due to battery failure. Therefore these systems are ineffective precisely at the time when they should be effective to prevent the sinking of the vessel during an emergency.
It will be appreciated that a seacock is any valve that is below the water line and is utilized for instance to admit raw sea water into such devices as an engine, a refrigeration unit or a water purification unit, or for shooting out waste.
As will be appreciated, the operator of the vessel is supposed to close all of the seacocks when the vessel is moored, because if a hose pops off and if it is below the water line, sea water floods the boat, filling it quickly and the vessel sinks.
While relatively large ocean going vessels have hydraulically controlled sea water valves, due to the fact it takes so much force to open these large valves, smaller boats are left to manual operation of their seacocks.
While operators of smaller boats want to be able to close the seacock or valve causing the trouble, they may also want to be able to leave other valves open, for instance to leave the raw water intake seacock for the engine open. Moreover, it may be desirable to have a seacock open if the faulty seacock or line is to a non-critical unit such as a head. It is thus important to be able to shut off the affected seacock without closing an unaffected seacock. Thus, it is desirable to be able to leave selected seacocks open, especially the seacock that is utilized to provide for the ingest of water to cool an engine, if the engine seacock is functioning correctly.
On the other hand, prior to ascertaining what seacocks and lines have failed, one would very much like to have a convenient and fail safe system for closing all of the seacocks to allow the operator to figure out which seacock or associated line is leaking or has failed. Once the leaking seacock has been diagnosed, it is desirable to have the operator can keep open the seacocks that are working properly.
For instance, if one is offshore fishing and one has discovered that a seacock is leaking, one could still operate un-affected equipment while simply keeping the affected seacock closed, allowing the boat to reach port where the affected seacock and associated line can be repaired.
Additionally, in terms of manual operation of seacocks or thru-hull valves, often-times manual operation requires a lever that is six inches long. There must thus be at least 6 inches of clearance around the seacock in order to be able to manually activate the seacock valve. Since these seacocks are in inaccessible spaces, it is either inconvenient or near impossible to be able to manually close a seacock. Moreover, depending on the seacock size and style it usually takes about 35 pounds of pressure to open and close a seacock, which means it takes 70 pounds of force that one has to exert on the seacock valve in order to open or close it. For many seacocks they are in a place where one cannot physically exert that much force on the valve.
Prior systems have been utilized to close off water inlet valves such as illustrated in U.S. Pat. Nos. 6,786,782; 5,947,047; 6,343,965; and 4,697,535. It is apparent from the above that there are no retrofit pneumatically operated systems to close all seacocks either for convenience or in an emergency.
Those systems requiring electricity are shown in U.S. Pat. Nos. 5,947,047 and 4,697,535, both of which operate with electrical power to close valves. It is important not to have electrically operated seacocks because the seacocks are located in a very damp and corrosive environment. It is noted that electrical systems generally do not last indefinitely in such environments. As mentioned above, when the sea water gets above battery level, the entire electrical system shorts out and one has no electricity aboard.
Referring now to U.S. Pat. No. 6,786,782, it will be appreciated that pneumatic valve actuation is described. However, it can be seen that the pneumatic valve actuator is placed on top of the seacock, meaning that an additional piece of apparatus must be added in series with the seacock to be able to shut off the water flow. A pneumatically actuated valve in series with the seacock is both cumbersome because it adds additional structure on top of the seacock, and is also counterproductive in that a failure can occur between the seacock and the pneumatically actuated valve. As a result, its use with existing seacocks is problematic.
In order to close a particular valve utilizing this patent, positive pressure must be maintained in order to keep the valve closed. Thus, for instance, in the piston arrangement shown, since it is spring loaded to keep the valve open, pressure must be continuously applied to the piston in order to keep the valve shut. This requires a constant source of pressure and a large reservoir.
Further and as will be appreciated, U.S. Pat. No. 6,343,965 relates to a pneumatically-actuated marine engine water drain system in which the water drains into the bilge of a boat or overboard. However, as can be seen, here there is no seacock.
Most importantly, not shown in the above-described art is the ability to close all of the seacocks in an emergency situation in which pneumatic closure overrides the actuation of any of the open seacocks. Moreover, nowhere is shown the ability to selectively open unaffected seacocks so that once the emergency situation has been addressed through the closing of all the seacocks, non-critical seacocks can be reopened for normal operation.